Data communications in a conventional network may be Internet Protocol (IP) data communications based on Layer 3 IP addresses. However, IP hosts in a same network segment are often in a same Layer 2 network, and these IP hosts (a Personal Computer (PC), a server, etc.) are interconnected by a switching device to form a Layer 2 communication network, so as to meet communication demands of hosts in the network. Two hosts, which are communicating with each other, may perform a communication in the manner of Layer 2 traffic forwarding, after resolving Layer 2 and Layer 3 addresses. The switching device may forward Layer 2 traffic, by identifying a source Media Access Control (MAC) address and a target MAC address in a Layer 2 packet header of the traffic.